Elements, Compounds, Mixtures
Warm Up Activity

This picture show the atoms that are
present in the air.
1. Which ones are elements?
2. How can you tell?
What do we call these
things?
An Atom
3 Atoms
What do we call these
things?
6 Atoms of 3 different
elements.
What do we call these
things?
A Molecule of an
element
• We don’t call it “2 atoms joined
together” we say it is one molecule.
• Since the atoms are the same, it is
also an element, not a compound.
What do we call these
things?
A Molecule of a
compound
* Notice that these
molecules have
different atoms in
them, so they are
compounds, not
elements.
2 molecules of a
compound
What about when all
the atoms are stuck
together like in a
solid element?
This is just a load of
atoms in a solid
element, it is not a
big molecule
Finally, just to confuse you even more,
science teachers like talking about
Particles
A particle is just a fancy name for individual
things. These individual things could be
atoms, molecules, lumps of soil, grains of
sand, or bits of metal. It doesn’t matter
because particle is just a general word
which is used when we don’t want to be
exact about the type of things being
described.
A good example of when science
teachers use the word particle is when
talking about air.
Air is a mixture of elements such as oxygen,
argon and nitrogen mixed with compounds
such as carbon dioxide, or you can say that air
is a mixture of particles.
Some of the elements in air go around
as single atoms (such as argon).
Or as molecules such as oxygen.
Compounds go around as molecules.
Since there is just one atom, you
would write: Ar
Ar
If there’s just one
atom, don’t put a
number after it!
O
Since there are two atoms of the
same element, you would write O2
Since there are different
you would list both: H2O.
O
Since there’s 2
oxygen atoms, you
write a “2” after the
elements,O
H
O
H
One Element
(Gas)
The Same Element
(Solid)
Notice that both examples are made
up of only one type of atom. That’s
why it is an element.
Another element
This one likes to go
round in pairs as a gas
(molecules)
A mixture of two
elements
Notice the mixture has
more than one type of
atom in it.
This a COMPOUND of
two different elements
Notice there are
two different
types of atoms
joined together.
That’s what
makes this a
compound.
This is just a
mixture of two
elements
Notice in a
mixture the all
the molecules
are not the
same.
Element, Compound
or Mixture ?
Element
Element, Compound
or Mixture ?
Element
Element, Compound
or Mixture ?
Mixture of different elements
Element, Compound
or Mixture ?
Mixture of different
elements
Element, Compound
or Mixture ?
Compound
Element, Compound
or Mixture ?
Compound
Element, Compound
or Mixture ?
A mixture of a
compound and
an element